1. Field of the Invention
The present invention relates to a toner conveying device. More specifically, the present invention relates to a toner conveying device capable of preventing the aggregation or cohesion of toner from occurring. In addition, the present invention relates to a developing device which develops an image with magnetic toner (hereinafter, referred to as “toner”) by means of an electrophotographic developing method. More specifically, the present invention relates to a developing device which prevents the aggregation of toner from occurring, and an image forming device having the same.
2. Background Information
Generally, in an image forming device in an electrophotographic developing method, such as printers, facsimiles, and copying machines, a developing device is provided for containing developer with which an electrostatic latent image formed on a surface of a photoconductor on the basis of original image data is developed into a toner image.
Here, in such a conventional developing device, if toner fluidity in the developing device has deteriorated, toner conveyance performance will be lowered such that the toner is apt to accumulate in a toner container. As a result, following an extended period of use, the toner accumulated in the container will clump together, and the aggregated toner will attach to a spiral member therein having a spiral shaped blade. Even if the toner is agitated, the aggregated state of the toner will not be eliminated, and will result in the occurrence of abnormal images, such as toner fogging. This type of problem also arises in an image forming device with a toner recycle mechanism in which residual toner on a photoconductor (an image support member) is removed by a cleaning device, and then returned to a developing device through a toner conveyance device utilizing a conveyance screw so as to be recycled.
A variety of image forming devices have been proposed in order to solve the above described problems. For example, the device disclosed in Japan Unexamined Patent Publication No. 2004-177754 has a rotary drive type conveying means for returning toner removed by a cleaning device to a developing device, and a toner smashing member for smashing aggregated toner remaining in the recycled toner. The toner smashing member is made of an elastic film sheet (PET film sheet), and has a tong member which is deformed by a force applied from outside during the rotation of a rotary driving type conveying means having a spiral shape. Thus, the toner smashing member having the tong member smashes the aggregated toner.
However, in the above-described conventional image forming device, the toner smashing member is designed to move only in the direction in which the spiral shaped blade of the rotary driving type conveying means travels (that is, the smashing member is elastically deformed only in the longitudinal direction of the shaft of the rotary driving type conveying means), and therefore, it is impossible to adequately scrape toner off the spiral shaped blade and the shaft of the rotary driving type conveying means. As a result, a conventional image forming device is unable to adequately reduce the occurrence of toner aggregation.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved toner conveying device, a developing device, and an image forming device having the same, which are able to prevent the occurrence of toner aggregation with a simple structure. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.